[llvm-commits] PATCH: Fix or PR13392 and many other slow-opt-compile bugs in LLVM

[Duncan Sands]

Hi Chandler,

>      > @@ -1867,9 +1866,20 @@ void SROA::isSafeMemAccess(uint64_t Offset,
>     uint64_t MemSize,
>      >        return;
>      >      }
>      >    }
>      > +
>      >    // Check if the offset/size correspond to a component within the
>     alloca type.
>      >    Type *T = Info.AI->getAllocatedType();
>      > -  if (TypeHasComponent(T, Offset, MemSize)) {
>      > +  if (Type *EltTy = getComponentType(T, Offset, MemSize)) {
>      > +    // If access is untyped (memcpy, etc), and the element being accessed is
>      > +    // an array, disable SROA to prevent exploding the memory intrinsic into
>      > +    // element-wise accesses to the array, unless the total size is
>     within the
>      > +    // scalar load threshold where we can turn it into an integer memory
>      > +    // access.
>      > +    if (!MemOpType && EltTy->isArrayTy() &&
>
>     Is this really specific to arrays?  Couldn't you get the same thing for structs?
>
>
> We can perform actual loads and stores of structs as a single load or store
> instruction, but we can't do that for arrays.

we can't?

Ciao, Duncan.